HAVi, home audio/video initiative, is a digital audio visual (AV) networking initiative that provides a home networking software specification for seamless interoperability among home entertainment products. The HAVi specification actually defines a set of criteria that enables compliant AV devices to interoperate in a home network. The specification lays down application program interfaces, APIs, which can be, used by programmers to build applications that ran on such networks, controlling devices irrespective of vendor or specific model characteristics.
Typically, a home audiovisual system will include a number of devices. Examples of such devices are televisions, radios, CD players, a pair of speakers, VCRs, DVD players, etc. Many of these devices may be produced by different manufacturers and function independently of the other AV devices owned by a user. The HAVi network allows interoperability between these devices. As each device becomes known to the HAVi network, it is added to the HAVi networking system. Each appliance is automatically registered by HAVi so that other devices know what it is capable of. Since HAVi has standardized the APIs of the most common AV functions, this interoperability is possible.
For example, a VCR integrated into the HAVi network can search for an appliance that offers a clock with the time-of-day also on the HAVi network, and automatically set its own timers. This may be done with the HAVi network without the aid of a home personal computer (PC).
The interconnection medium used in a HAVi network is IEEE 1394. The IEEE 1394 serial communication bus standard (1394) is used as a local bus platform to provide the common messaging system. It carries commands and status information as well as digital audio and digital video signals between devices. Generally, 1394 has been a good interconnection medium because it has more than enough capacity to simultaneously carry multiple digital audio and video streams around the house. Also, 1394 provides support for digital copy protection.
While IEEE 1394 enables HAVi systems to offer guaranteed high levels of service, it restricts the range of devices that can participate in the home network. Generally, electronic devices made for home entertainment purposes are becoming more and more complex and with greater capabilities. This is in direct correlation with the continuing emergence of a wide range of low cost, high-quality wired and wireless networks and end-systems. Many of these devices are considered a part of the home AV network but do not support 1394 connections. Instead, these devices usually support Internet Protocol (IP) on a wide range of wired/wireless networks such as the Internet. Examples of such devices are personal digital assistants (PDAs) oriented to home audio visual (AV) and MP3 players such as a MusicClip™ player manufactured by Sony Corporation.
Consumers are also increasingly purchasing such devices. As they purchase these devices, the HAVi network should allow these devices to be connected to the HAVi network regardless of a lack of 1394 support.
Currently, the HAVi specification accommodates the connection of non-1394 devices as extensions to 1394 devices when connected. The DCM for a hosting device is extended with the connected device functionality. However, this approach does not extend the HAVi network to IP devices. Also, it does not support running HAVi applications on IP devices.
One approach to integrate IP devices into the HAVi network may be to reengineer or rewrite the HAVi specification to integrate internet protocol devices into the HAVi network. Wholesale changes in the HAVi specification, however, may be costly and inefficient. Therefore, what is needed is a fairly cost-efficient method and apparatus for integrating IP devices into a HAVi network.